INTERFERENCE-OPTICAL FORCE SENSOR FOR SMALL FORCES

Gerd Jäger, Roland Füßl
Abstract:
Force measurement at a resolution in the micronewton range is advantageously performed by means of electromagnetic force compensation. So far, weighing systems of this kind have been working only in a horizontal position. Although resistance strain gauge force sensors are suited to various force directions, they cannot be used for precision measurements in the micronewton range.
In this paper, an interference-optical force (IOF) sensor is described which can be used both for horizontal and vertical force measurement. The force measuring range of a specially designed force sensor amounts to 100 mN (10 g), resolution to 0.01 mN, and the extended measuring uncertainty to 0.008 mN for k = 2. The structure, the operating principle and the signal processing of the force sensor are described and, furthermore, a uncertainty of measurement analysis of the entire system is made. The successful application of the interference-optical force sensor is finally demonstrated by means of the example of the calibration of applanation tonometers.
Keywords:
force measurement, laser interferometer, horizontal force measurement
Download:
PWC-2003-TC3-003.pdf
DOI:
-
Event details
Event name:
XVII IMEKO World Congress
Title:

Metrology in the 3rd Millennium

Place:
Dubrovnik, CROATIA
Time:
22 June 2003 - 28 June 2003